1. Field of the Invention
This invention relates to products incorporating piezoelectric material, and is more particularly but not exclusively concerned with such products in the form of sports shoes, balls and fishing lures.
2. Prior Art
It has already been proposed, for example in U.S. Pat. No. 4,748,366 to Taylor, to provide dancing shoes and a child's ball each incorporating a layer of piezoelectric material and a light source. The piezoelectric material and the light source are directly electrically connected together so that the electrical energy produced by the piezoelectric effect upon impact of the shoe or ball against the ground or other surface, directly energizes the light source.
However, the amount of electric energy normally produced in response to a typical impact is insufficient to produce readily visible energization of the light source, i.e. energization of the light source which is clearly visible in daylight and/or of significant duration.
Numerous U.S. references describe lighted shoes, shoes incorporating piezoelectric materials, other articles incorporating piezoelectric materials and pressure sensitive articles, see, for example the following:
U.S. Pat. No. 1,597,823 to Randolph discloses a shoe having an illuminating means disposed within the heel thereof. The illumination means is controlled by a manual switch mechanism. U.S. Pat. No. 3,239,696 to Burkhalter, et al. discloses a piezoelectric pressure transducer that responds to pressure variations ranging from subaudio frequencies into, at least, the audio range. The transducer is used in sphygmomanometry to measure the systolic and the diastolic limits of blood pressure variation and for other medical applications.
U.S. Pat. No. 3,323,367 to Searle discloses a grip indicator for measuring the pressure exerted by a player on a club or racquet. The grip indicator comprises one or more sensors whose electrical resistance changes when compressed and a meter and bridge circuit to measure this change.
U.S. Pat. No. 3,549,878 to Bailey. discloses a light distribution system for distributing a pattern of light over the clothing of a wearer. In a typical embodiment, plunger-type switches are mounted in various locations in the shoes of a wearer. Pressure imparted to various parts of the shoes, as in dancing, activates these switches. These switches, in turn, activate corresponding switches which control the amount of current applied to a piezoelectric spiral. Variations in the current applied to this spiral cause the spiral length to increase thereby rotating the tip of the spiral. This rotational motion of the spiral tip is used to control the rotation of a multicolor light filter and thus change the pattern of light produced.
U.S. Pat. No. 3,582,691 to Sonderegger, et al. discloses a force transducer unit comprising piezoelectric elements mounted so as to divide the external forces applied into exactly defined partial forces.
U.S. Pat. No. 3,582,692 to Palini discloses an improved piezoelectric transducer responsive to changes in pressure and a circuit for activating a reed relay. The transducer includes a piezoelectric element, a pair of electrodes on opposite sides of the element, means for supporting the element, and an actuator means connected to the element for applying pressure to the element.
U.S. Pat. No. 3,604,958 to Palini discloses a transducer for use in a security device to protect objects from unauthorized removal. The device senses both increases and decreases in pressure and provides an output signal indicating pressure changes. The transducer includes a piezoelectric element and an actuator for transmitting pressure to the piezoelectric element. When either an increase or decrease in pressure occurs, the piezoelectric element produces an output signal. This output signal decreases the conductivity of a unidirectional current device which then activates a warning circuit.
U.S. Pat. No. 3,750,127 to Ayers, et al. discloses a piezoelectric sensor used as a strain gauge, an intrusion detector, or a thermal gradient detector. The piezoelectric sensor produces an electrical signal proportional to the amount of strain or deformation sensed.
U.S. Pat. No. 3,798,474 to Cassand, et al. discloses a pressure wave sensor having a piezoelectric element with two faces. Each face is associated with a flexible conducting electrode over the entire length of the sensitive element. The sensor may be used for measuring pressure variations resulting from seismic vibrations in the sea or on the earth.
U.S. Pat. Nos. 3,893,247 and 3,946,505 to Dana, III disclose shoes having illuminated sole and heel portions. A battery circuit and lamp source are located in the heel and/or sole of the shoe. The lamp is turned on and off by a tilt switch and/or a manually actuated switch.
U.S. Pat. No. 3,974,491 to Sipe discloses a device for activating a buzzer when a predetermined load is placed on one's foot. The device comprises a resilient liquid-filled tube mounted within a foot pad, the tube extending from adjacent the toe end of the foot pad to adjacent the heel end. Pressure on the liquid compresses a spring which at a predetermined pressure causes the buzzer to activate.
U.S. Pat. No. 4,020,572 to Chiaramonte, Jr. discloses a shoe platform having an illuminated sole. A lamp circuit and battery are located in the platform and controlled by a manual switch.
U.S. Pat. No. 4,054,808 to Tanaka discloses a vibration detecting device for use with musical instruments for detecting vibrations therein. The device comprises a structure containing a piezoelectric ceramic plate housed in a case.
U.S. Pat. No. 4,112,601 to Chiaramonte, Jr. discloses a shoe having a high-intensity lamp, a battery, a light modulator and filters for emitting a sequence of colored light from the lamp. The colored light is emitted through a light transmitting material comprising the riser of the shoe.
U.S. Pat. No. 4,128,861 to Pelengaris discloses an illuminated shoe having a lamp and battery circuit disposed within the heel of the shoe and a means for activating the lamp comprising contacts on the heel of the shoe. Upon application of pressure to the heel, these contacts are pressed together, the battery circuit closes and causes the lamp to light.
U.S. Pat. No. 4,130,951 to Powell discloses an illuminated dancing shoe having an flashlight mounted in the heel and a bundle of optical fibers which extend from the flashlight through the sole to various points around the edge of the sole. The flashlight is turned on and off by a spring operated pressure switch. This switch turns on the flashlight when the wearer applies pressure to the heel of the shoe such as by resting or tapping the heel on the dance floor.
U.S. Pat. No. 4,158,117 to Quilliam, et al. discloses a pressure sensitive switch that includes a polyvinylidene fluoride sheet polarized to render it piezoelectric and a manual push button. Pressing the push button compresses the polyvinylidene fluoride sheet which then generates an electrical signal.
U.S. Pat. No. 4,158,922 to Dana, III discloses a lighted shoe wherein a built-in solid state oscillator (or a tilt switch) and battery circuit flashes a lamp so as to light the transparent portion.
U.S. Pat. No. 4,216,403 to Krempl, et al. discloses a transducer having a piezoelectric measuring sensor element for measurement of mechanical values on hollow bodies, especially pressure distribution within pipes.
U.S. Pat. No. 4,253,253 to McCormick discloses an ornamental shoe having a transparent heel with a battery circuit and a lamp. When the lamp is turned on, it lights the transparent heel. U.S. Pat. No. 4,304,126 to Yelke discloses a transducer for sensing and monitoring the injection of fuel into a fuel injection engine. The transducer includes a piezoelectric element mounted on the fuel line to sense the change in the circumferential dimension of the line due to pressure surges in the line.
U.S. Pat. No. 4,328,441 to Kroeger, Jr., et al. discloses a pressure sensitive apparatus for producing electrical signals on two electrodes. The apparatus includes a conductive layer, a piezoelectric polymer film layer, an electrode layer, an insulating layer, another electrode layer, another piezoelectric polymer film layer and another conductive film layer. This reference teaches the use of both high impedance voltage sensing interface circuits and low impedance current sensing interface circuits to process the signal output by a piezoelectric sensor.
U.S. Pat. No. 4,402,147 to WU discloses an electronic counter mounted in the toe of a shoe which counts the number of steps taken. Contact switches that close when walking a step activate counter circuitry which then causes a digital display to either count up or count down.
U.S. Pat. No. 4,499,394 to Koal discloses a piezoelectric sensor attached to the foot of an animal to continuously measure the pressure of the animal's foot against a reactive surface. The sensor and associated circuitry is electrically interconnected with telemetry and analyzing apparatus.
U.S. Pat. No. 4,510,704 to Johnson discloses a mechanical or electronic pedometer which is contained in the heel of a shoe. The pedometer detects when a step is taken. In the electronic counting embodiment, the pedometer includes electronic counting and processing circuitry, a battery, an impulse transducer (i.e. a piezoelectric element) to trigger a count, and an electronic display of the total count.
U.S. Pat. No. 4,660,305 to Medler, et al discloses a tap dance shoe wherein impact sensors including piezoelectric transducers are contained in the taps attached to the dance shoe. The sensor produces an electrical signal when the tap strikes the dance floor. This electrical signal is then transmitted for remote processing and amplification.
U.S. Pat. No. 4,703,217 to Ratzlaff, et al discloses a piezoelectric transducer mounted on a horseshoe to enable measurement of the forces generated when a horse's hoof contacts the ground. The signal from the piezoelectric transducer is amplified and processed by electronic circuitry so that its information content can be stored and used in scientific studies of a locomotion pattern.
U.S. Pat. No. 4,778,366 to Taylor discloses novel uses of piezoelectric materials for creating optical effects which are directly powered by the electrical energy generated by the piezoelectric materials. The piezoelectric material is incorporated into an article manufacture such that by using the article, mechanical energy is imported to the piezoelectric material, thus causing the generation of an electrical voltage. The voltage is tranferred to an optical effect device which can be activated by the high voltage, low current output of the piezoelectric material. Such devices include electroluminescent materials, gas discharge (plasma) panels, neon bulbs and liquid crystal devices. The output of the piezoelectric material is directly coupled to the optical effect device. This reference also teaches the use of layers of piezoelectric material to generate the energy required to activate the optical effect.
U.S. Pat. No. 4,771,394 to Cavanagh discloses a pair of running shoes provided with a housing at the heels in which an electronic footstrike counting device may be removably mounted thereon. The electronic device is cabled to a computer before and/or after usage of the shoes to transfer footstrike count and run time data to the computer or to have the computer preprogram the electronic device with distance data so that when a given distance is completed, a tone will sound. The electronic device includes an inertia switch for producing a foot strike count. U.S. Pat. No. 4,814,661 to Ratzlaff, et al. discloses a system for measuring and analyzing the forces exerted during running or walking. The system includes piezoelectric sensor elements mounted on a plate which may or may not be incorporated into a shoe. The plate extends under all or portions of the plantar surfaces of a human foot to provide accurate foot force detection during unrestrained motion.
U.S. Pat. No. 4,824,107 to French discloses a martial arts sports scoring device wherein piezoelectric film is mounted on protective equipment such as headgear, handgear or footgear, protective vests and the like. The piezoelectric film produces an electrical signal with an amplitude corresponding to the force of a blow or the degree of deformation of the film. The electrical signal can be processed by electronic circuitry to count the number of blows or to measure the amount of force of each blow. The results of this analysis can be displayed on various types of displays including meters or a bar of light emitting diodes, or these results can be converted into audible tones.
U.S. Pat. No. 4,848,009 to Rogers discloses footwear having a motion responsive switch, a battery, a timing circuit, and a lamp, preferably a light emitting diode. This reference teaches using a motion responsive mercury switch that alternates states in response to the motion of the footwear. When the motion causes the switch to activate (ON), a timing circuit is activated and the lamp is lit. After a predetermined time, the timing circuit turns off the lamp and prevents the lamp from being turned on again until the motion responsive switch makes an OFF transition and then an ON transition. Thus this reference teaches turning a lamp ON again only in response to a change in orientation of the footwear after the timing circuit times out. This reference does not teach lighting a lamp in response to pressure or impact on a sensor embedded in an athletic shoe.
U.S. Pat. No. 4,991,150 to Wixom discloses a dynamic mechanical stress transducer comprising a piezoelectric material in intimate electrical communication with an electroluminescent material that emits light at an intensity in proportion to the magnitude and rate of change of the stress applied to the piezoelectric material. In a preferred embodiment, the electroluminescent material comprises a light emitting diode.
References uncovered relating to toys, for example balls, are:
U.S. Pat. No. 3,580,575 to Speeth discloses an impact toy, such as a ball, with a circuit, impact operated switches and three colored lamps mounted in the interior. Upon impact of the toy, one of the three switches closes and a corresponding lamp lights.
U.S. Pat. No. 3,610,916 to Meehan discloses an illuminable ball with an inertia switch and a time delay circuit. The ball is translucent and within the ball is an inertia switch which triggers a time delay circuit that then applies battery power to two lamps. Power is applied for a duration preselected by the time delay circuit.
U.S. Pat. No. 4,595,200 to Shishido discloses a sound emitting ball. In one embodiment, the external impact force is detected by a piezoelectric sensor which triggers electronic processing and amplification circuitry. This circuitry then causes a piezoelectric speaker to emit a buzzer sound or a melody sound.
U.S. Pat. No. 4,737,134 to Rumsey discloses a ball that produces audible tunes corresponding to the amount of light that falls upon a light transducer mounted on the surface of the ball. An oscillator is coupled to the light transducer and to a speaker to produce the tones. A motion switch turns off the audible tone when the ball is at rest for a preset time period.
References uncovered relating to fishing lures are:
U.S. Pat. No. 3,828,177 to Day discloses a fishing lure having a battery and a lamp disposed therein. A bundle of optical fibers extends from the lamp to the exterior of the lure to conduct light to the outside of the lure.
U.S. Pat. No. 3,940,868 to Northcutt discloses a fishing lure having a battery and a light emitting diode that is turned on by a water activated switch.
U.S. Pat. Nos. 4,250,650 and 4,347,681 to Fima discloses a fishing lure containing one or more lamps and a guideway along which a battery rolls as the lure moves. Movement of the battery along the guideway intermittently completes a lamp circuit and turns on the lamps. The light from these lamps is transmitted by optical fibers to the surface of the lure.
U.S. Pat. No. 4,741,120 to Cota, et al discloses a self-illuminating fishing lure having a constant light source produced by a tritium capsule encapsulated within a hard translucent fish lure body.
Foreign references uncovered relating to this invention are:
Italian Patent No. 489,219 to Valentino discloses a shoe with an on/off switch and a lamp in the heel which illuminates the heel.
French Patent No. 1,555,306 to Deus, et al. discloses an illuminated shoe having a piezoelectric transducer, which when compressed, lights a lamp.
French Patent No. 2,227,714 to Rich discloses a shoe with an illuminated heel having a battery, a mercury switch, a relay and a lamp arranged within the heel so that when the shoe is in a flat position, the lamp is turned off.
French Patent No. 2,556,190 to Hume discloses a shoe having a battery powered flashing lamp in the heel. Lamp current passing through a bimetallic switch heats the switch thereby opening the lamp circuit; the bimetallic switch then cools and closes the lamp circuit, thus causing flashing of the lamp.
Netherlands Pat. No. 8006456 to Maria De Nijs, et al. discloses a battery circuit, a switch, a lamp or light emitting diode, a colored bead, and an optical fiber interconnecting the lamp with the colored bead.
Japanese Application No. 58-195238 to Daitou discloses an electro-mechanical transducer comprising a high polymer film having localized piezoelectric properties. This transducer may be used as a contactless keyboard.
European Patent Application No. 83 307822.3 to Dana III discloses a shoe having a lamp or light emitting diode, a battery circuit and a mercury switch or a mechanically activated pressure switch to light or flash the lamp. Flasher circuitry can be added which is manually activated by the wearer. In addition, the flasher circuits and battery can be encapsulated.
German Patent No. 26 08 485 to Ben-Hassine discloses an illuminated shoe heel having a battery circuit and a mercury switch for turning on and off a plurality of lamps or light emitting diodes mounted through the surface of the shoe heel. The mercury switch turns off the lamps when the heel is raised.
International Application No. PCT/AU86/00324 to Hopper discloses a touch or proximity switch that incorporates a light emitting diode to visually indicate the on or off state of the switch. A piezoelectric stress sensor may be used to trigger circuitry that lights the light emitting diode and to trigger a solid state switch or a transistor.
PCT/US80/01677 to Kroeger, Jr., et al. discloses a pressure sensitive apparatus for producing electrical signals on two electrodes. The apparatus comprises a layered structure including a conductive layer, a piezoelectric polymer film layer, an electrode layer, an insulating layer, another electrode layer, another piezoelectric polymer film layer and another conductive layer. Kroeger teaches the use of a high-impedance interface such as a digital gate or an operational amplifier circuit to sense the voltage generated by the pressure sensitive piezoelectric sensor.
Other references uncovered are:
Biomechanics VII-B, International Series on Biomechanics, Volume 4B, Proceedings of the Eighth International Congress of Biomechanics, Nagoya, Japan, 1983, discloses a shoe having an array of piezoelectric transducers embedded in silicone rubber and inserted into the mid-sole of a shoe. These transducers are used to obtain force measurements for studies on the interaction between the foot and the shoe while walking. The device further includes a back pack containing amplification and multiplexing circuitry. Medical and Biological Engineering and Computing, Foot-Force Measuring Device for Clinical Assessment of Pathological Gait, Miyazaki, et al., July 1978, discloses a force transducer that is attachable to a shoe, in combination with an amplifier transmitter and a receiver processor unit for measuring the static and dynamic forces acting between the foot and the floor during walking. The Complete Handbook of Athletic Footwear, Cheskin, Melvyn P., Fairchild Publications, New York, 1987, P. 158, discloses a flashing safety light component for use with running shoes. The device is attachable, by cement, to the heels of running shoes and functions as a night-running safety device.
None of the foregoing references teach or suggest the invention claimed herein.